The Collaborative International Dictionary of English v.0.48:

Evacuate \E*vac"u*ate\, v. t. [imp. & p. p. Evacuated; p. pr.
   & vb. n. Evacuating.] [l. evacuatus, p. p. of evacuare to
   empty, nullify; e out + vacuus empty, vacare to be empty. See
   Vacate.]
   1. To make empty; to empty out; to remove the contents of;
      as, to evacuate a vessel or dish.
      [1913 Webster]

   2. Fig.: To make empty; to deprive. [R.]
      [1913 Webster]

            Evacuate the Scriptures of their most important
            meaning.                              --Coleridge.
      [1913 Webster]

   3. To remove; to eject; to void; to discharge, as the
      contents of a vessel, or of the bowels.
      [1913 Webster]

   4. To withdraw from; to quit; to retire from; as, soldiers
      from a country, city, or fortress.
      [1913 Webster]

            The Norwegians were forced to evacuate the country.
                                                  --Burke.
      [1913 Webster]

   5. To make void; to nullify; to vacate; as, to evacuate a
      contract or marriage. [Obs.] --Bacon.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Evacuate \E*vac"u*ate\, v. i.
   1. To let blood [Obs.] --Burton.
      [1913 Webster]

   2. to expel stool from the bowels; to defecate.
      [PJC]

WordNet (r) 3.0 (2006):

evacuate
    v 1: move out of an unsafe location into safety; "After the
         earthquake, residents were evacuated"
    2: empty completely; "evacuate the bottle"
    3: move people from their homes or country
    4: create a vacuum in (a bulb, flask, reaction vessel)
    5: excrete or discharge from the body [syn: evacuate, void,
       empty]

Moby Thesaurus II by Grady Ward, 1.0:

88 Moby Thesaurus words for "evacuate":
   abandon, abscond, back out, beat a retreat, beg off, blow,
   blow out, bow out, breathe out, ca-ca, clean out, clear,
   clear away, clear off, clear out, clear the decks, crap, cry off,
   defecate, depart from, deplete, deprive, desert, disappear,
   discard, discharge, divest, drain, drop out, dung, eliminate, emit,
   empty, empty out, exhale, exhaust, expire, forsake, fume,
   get rid of, give off, give out, give vent to, go back on, jettison,
   jilt, leave, leave behind, leave flat, let out, maroon, move,
   number two, open the floodgates, open the sluices, puff, pull out,
   purge, quit, quit cold, reek, relinquish, relocate, remove, renege,
   retire, retreat, say goodbye to, scour out, shit, smoke,
   stand down, steam, stool, sweep out, take a shit, take leave of,
   throw off, throw over, unclog, unfoul, vacate, vanish, vapor, vent,
   void, withdraw, withdraw from